中文摘要：

基于常规环境演变指标的研究结果显示，大规模陨击事件的确可以造成地球环境的突变，但是对陨击事件期间水生或陆地植被类型变化的研究却并不多见。因此，通过统计南塔斯曼海大洋钻探计划（ODP）1170站位（47°9．0344’S，146°2．9846’W；水深2705m）B孔16—15m（mbsf）沉积物中微玻陨石颗粒丰度，结合有孔虫壳体氧、碳同位素（δ18O和δ13C）、表层海水温度（SeaSurfaceTemperature，简称SST）等常规参数指标，分析了不同生物标志物含量变化，重建了陨击事件过程中海洋与陆地植被结构的演变历史。结果发现：1）南塔斯曼海ODP1170站位沉积物中微玻陨石颗粒丰度峰值出现在15．55～15．45m，且根据生物地层确定来源于0．8Ma前后的澳大利亚陨击事件（Australian Meteorite Impact Event，简称AMIE），其中微玻陨石颗粒最多出现在15．50m，颗粒丰度达9．4枚／g；2）AMIE导致SST下降约1．7℃，颗石藻与硅藻的含量比值由15．58m的约6突然下降到15．50m的约2．6，显示表层海水环境向有利于硅藻等生存的方向发展，同时烷烃C15-19与C24-25的含量突然下降约50％，显示表层海水环境向不利于菌（藻）类或其他浮游植物等生存的方向演化；3）AMIE对陆地植被种类的演化及陆源有机质输入的影响有限，并且在微玻陨石丰度下降的15．45～15．30m深度；ACL，C31／C29和∑Odd（C25-33）却突然增加，显示陆源植被种类变化对AMIE的响应可能存在一定程度的滞后。

英文摘要：

The impact of extraterrestrial meteorite to the earth could induce markedly environmental changes based on some widely used paleoenvironmental proxies. The response of marine and land vegetations to the impact event, however,is rarely reported. In this paper,the influences of the impact event on marine and land vegetations through the analyses of microtektite abundance, different biomarkers, foraminiferal δ18O and δ13C , and Sea Surface Temperature（SST） records from the interval of 16 -15m（mbsf） in depth at ODP Site 1170B （47°9.0344＇S, 146°2. 9846＇W; water depth of 2705m） of the Southern Tasman Sea are studied. The results show that： （1）The peak of microtektites abundance occurs at the depth of 15.55 -15.45m,and these microtektites were caused by the Australian Meteorite Impact Event （AMIE）based on the biostratigraphy record, which occurred around 0.8Ma. Furthermore,the highest abundance of microtektites occur at the depth of 15.50m, about 9.7 grains/g; （2）The AMIE resulted in the decrease of SST by about 1.7℃ , and decrease of the ratio of coccolith/diatom from about 6.0 to about 2.6 from the depth of 15.58m to 15.50m, and decrease of the content of CI5_ 19 and C21-25 by around 50%. All of these results suggest that the AMIE induced tl3e surface water condition to be more favorable for diatom bloom,rather than photosynthetic bacteria or other algae ; （3） The influences of AMIE on the terrestrial vegetation structure and terrestrial organic matter input could be limited. The ACL, C31/C29 and EOdd （ C25-33 ） increased abruptly in the depth of 15.45m to 15.30m where the mierotektite abundance decreased, implying that the lagged response of the terrestrial vegetation structure to the AMIE in some degree.